Changes

Cast result of malloc

This is common practice in MSL.
It is mandatory when compiling external C code as C++.
Also mind the later cast in "return (void*) table" that is
neither required by C nor by C++, nevertheless expressing the intention.

User's Guide: add recommendation for 'tab' and 'group' annotations

Documentation: clarify mind-set of planar rotation

Improve EN grammar

Co-authored-by: Hans Olsson <HansOlsson@users.noreply.github.com>

Add a rule priorizing the 'general' tab

Add example how to define tab and group annotations

Enhance the 'Tabs and Groups' example

Remove newlines at end of Text primitive. (#4187)

Newline behavior in Text primitives is undefined, and in these cases seem to serve no purpose regardless.

Based on comments in #4156 just remove eps.

Update .mailmap file

Create by command

```
git log --raw | grep "^Author: " | sort | uniq | cut -d ' ' -f2- | sed 's/^//' > .mailmap
```

Remove call of localtime

There is a race condition between localtime and ftime/gettimeofday in ModelicaInternal_getTime. In case ftime/gettimeofday is called at a very new second, this can lead to a inaccuracy of (almost) 1 second for the calculated time.

Using gmtime, there is no need to call localtime. Instead the struct tm can be directly computed from the obtained timebuffer and timezone information.

Improve ElastoGap
Closes #4197

Prefer code to pre, and move things.

Add scaling ratio variable and add parameter description

Simplify computation of f_d

Documentation: add non-braking spaces where needed

Add scaling ratio variable and add parameter description

Simplify computation of f_d

Documentation: add non-braking spaces where needed

Improve documentation concerning s_rel and f_rel

Enable only positive values of s_rel and f_rel

- added partial massFraction to partialMedium
- implemented massFraction for partialPureSubstance
- implemented massFraction for PartialMixtureMedium
- added 3 test cases for ModeliceTest covering pure / reduced mixture / non-reduced misture

Update Modelica/Media/package.mo

Accepted suggestion

Co-authored-by: Thomas Beutlich <modelica@tbeu.de>

Use spaces instead of tabs